Question

A travelling wave passes point of observation. At this point, the time interval between successive crests is $0.2s$ and

• A. The wavelength is $5m$
• B. The frequency is $5Hz$
• C. The velocity of propagation is $5m/s$
• D. The wavelength is $0.2m$

Answer 1

The correct option is B The frequency is $5Hz$

$\begin{array}{c}Accorrdingtoquestion.......................\\ Here,\\ Differencebetweentwosuccessivecrestis2p.\\ passesdifference\left(\Delta \phi \right)=\frac{2\pi }{T}\\ T=timeinterval\left(\Delta t\right)\\ \therefore n=2\pi =\frac{2\pi }{T}\times 0.2\\ \Rightarrow \frac{1}{T}=5{\sec }^{-1}\\ \Rightarrow n=5Hz\\ SothecorrectoptionisB.\end{array}$